Physical Correlations and Predictions Emerging from Modern Core-collapse Supernova Theory

Abstract

In this paper, we derive correlations between core-collapse supernova observables and progenitor core structures that emerge from our suite of 20 state-of-the-art 3D core-collapse supernova simulations carried to late times. This is the largest such collection of 3D supernova models ever generated and allows one to witness and derive testable patterns that might otherwise be obscured when studying one or a few models in isolation. From this panoramic perspective, we have discovered correlations between explosion energy, neutron star gravitational birth masses, 56Ni and α-rich freezeout yields, and pulsar kicks and theoretically important correlations with the compactness parameter of progenitor structure. We find a correlation between explosion energy and progenitor mantle binding energy, suggesting that such explosions are self-regulating. We also find a testable correlation between explosion energy and measures of explosion asymmetry, such as the ejecta energy and mass dipoles. While the correlations between two observables are roughly independent of the progenitor zero-age main-sequence (ZAMS) mass, the many correlations we derive with compactness cannot unambiguously be tied to a particular progenitor ZAMS mass. This relationship depends on the compactness/ZAMS mass mapping associated with the massive star progenitor models employed. Therefore, our derived correlations between compactness and observables may be more robust than with ZAMS mass but can nevertheless be used in the future once massive star modeling has converged.

Dissecting the Crab Nebula with JWST: Pulsar Wind, Dusty Filaments, and Ni/Fe Abundance Constraints on the Explosion Mechanism

“…It can be seen that the modestly elevated Ni/Fe ratio in the Crab is consistent with the "mixed" Ni/Fe ratios for either an LMCCSN or an ECSN. These SNe also provide low enough explosion energies (listed in units of Bethes (B) in Figure 20) to be consistent with the Crab (Burrows et al 2024a;). The pulsar kick velocities resulting from the 3D models are also included in the plot.…”

“…There are theoretical indications that this may happen more easily for lower-mass stars (Woosley & Weaver 1995) and for asymmetric explosions (Nagataki et al 1997). While the more recent 1D explosion nucleosynthesis models of Sukhbold et al (2016) do not show this enhancement, a particularly asymmetric 3D model of an 11 M e progenitor (Burrows et al 2024a;) does indicate a Ni/Fe enhancement of ∼4 times solar (envelope included), though the resulting neutron star kick velocity of ∼700 km s −1 is too high compared to the 160 km s −1 velocity of the Crab's pulsar (see Figure 20).…”

“…CCSN. We will use this shorthand for Fe CCSNe that produce an explosion kinetic energy of 0.3 × 10 51 erg (e.g., Sukhbold et al 2016;Burrows et al 2024a). These should occur above an initial mass of roughly 10.5-11 M e , although the mass transition is not sudden and may differ from one set of models to the next.…”

“…These layers are too small in mass (10 −3 M e ) to affect the total Ni and Fe yields for intermediate-and high-mass progenitors (i.e., CCSNe from 11 to 20 M e progenitors) but may become relevant for lowmass progenitors with lower yields of Ni and Fe that produce LMCCSNe. The recent work by analyzing the nucleosynthesis of 3D Fe CCSN simulations (Wang & Burrows 2023;Burrows et al 2024a) found that the 9 M e progenitor model with some imposed initial velocity perturbations produced more neutron-rich material, leading to a final Ni/Fe abundance ratio of ∼8 times solar. This value reflects the ratio for the entire ejecta, including the stellar Figure 20.…”

“…The vertical lines reflect the variation in the expected ratio due to mixing with the stellar envelope (the dots are Ni/Fe values assuming no mixing with the envelope, and the crosses are values that assume the ejecta are mixed with the stellar envelope). The explosion energy (in units of Bethes) and resulting neutron star kick velocity are also labeled for each model (Burrows et al 2024a;) and can be compared to the ∼160 km s −1 kick velocity of the Crab's pulsar (Hester 2008;Kaplan et al 2008). Nucleosynthetic yields from the 1D Fe core-collapse models of Sukhbold et al (2016) envelope, so it is appropriate to compare it with the observed ratio in the Crab's filaments that might contain mixed-in outer ejecta layers or unprocessed CSM.…”